Electric motor



(No Model.) v

F. E. HBRDMAN.

ELECTRIC MOTOR.

No. 541,544. atented June 25, 1895.

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UNITED STATES PATENT OFFICE.

FRANK E. I'IERDMAN, OF IYINNETKA, ILLINOIS.

ELECTRIC MOTOR.

SPECIFICATION forming part of Letters Patent No. 541,544, dated June 25,1895.

Application filed November 27, 1894- Serial No. 530,092. (No model.)

To all when?, it may concern:

Be it known that 1, FRANK E. HERDMAN, a citizen of the United States,residing at Winnetka, county of Cook, and State of Illinois, haveinvented a new and useful Improvement in Electric Motors, of which thefollowing is a full, clear, and exact description, reference being hadto the accompanying drawings, which form a part of this specification.

My invention relates to that class of electric motors wherein thecurrent is initially admitted to the armature through resistances whichare gradually cut out of the armature circuit as the motor gains itsspeed, and this u is accomplished by providing resistances and an armadapted to travel oversaid resistances in the armature circuit, the armbeing so placed in reference to the resistance that when the current isinitially admitted to the armature with the greatest resistance in thearmature circuit, and this arm is caused to automatically travel overthe resistances cutting said resistances gradually out of the armaturecircuit until the full current strength is admitted to the armature.

My invention specifically relates to certain improvements to be usedwith a resistance arm whose brush rests upon insulation when the currentis cut ott, to enable the arm to be moved oit the insulation when thecurrent is turned on, and consists in a device connected with the switchmechanism whereby when the operating bar is moved so as to throw ou thecurrent, the arm will be moved by said device from the insulation to theresistances, but the device will not move said arm farther'.

In the drawings, Figure lis a diagrammatic view. Fig. 2 is a section onthe line Fig. 1. Fig. 3 is a section on the line c 'U ot' Fig. l. Fig. 4is a section on the line w w of Fig. l.

M is an electric motor; M being the eld magnets and M2 the armature.

A is the rheostat or resistances.

A is the armature resistance, and A2, the lield resistances.

A3 is the magnet in series with the armature, and A4 a contact.

B is the resistance arm adapted to be operated in one direction when thecurrent is admitted to the armature and iields, by mechanism such as isshown in an application tiled by me the same day as this application andadapted to be operated in the other direction by means of the weight, B.Attached to said shaft C is the reversing switch (see detail Fig. 3)consisting of a cylinder c having two sections, C and C2, separated byinsulation,c3. Thesectionsc-c2areconnected to the poles of currentsupply and brushes, a-a, adapted in the movement of the cylinder c,ineither direction to be brought in con` tact with the sections c-c2, cbeing brought in contact with c' 0r c2, and a with c2 or c', dependentupon the direction of movement of roller, C, the brushes a, a', beingconnected by wiring with the armature, the switch C being a reversingswitch, the brushes a, a', resting on the insulation when the switch iscentral.

I have shown the Wiring to the armature and to the field, the fieldwiring being denoted by letter te, and the armature wiring by y.

The circuit to the armature includes the resistance, A', and the circuitto field the resistances, A2.

A5 is insulation upon which the brush of the arm B rests when the motoris at rest. As it is necessary for the arm B to move from the insulationA5 to resistance A', before current is admitted to the armature even ifthe switch C, be operated so as to admit current to it, I provide thefollowing means: D is the cam, shown in detail Fig. 4, resting againstone end of the arm E, said arm being suitably supported in guides, e.,e', so as to be adapted to slide. The other end of the arm E restsagainst a pin, b, on the arm B, the pin being held against the arm whenthe arm is on the insulation, A5, by means of the weight, B. The cam Das shown in Fig. 4,isadouble faced cam, so that in the movement of thecam in either direction from the center, the

arm E is moved forward. This cam D is pro-l vided with a hub loose onthe shaft or prolongation of the shaft, c, of switch roller, C. This hubis connected to a disk F, also loose on said shaft. This disk isprovided with three notches,f,f,f2. On each side of this disk arepivoted spring fingers, F, F2, held against it by the springs.Frictionally connected with this disk F, is the disk G, fixed to theshaft and carrying the spring clutch, Gr', the disk plates of which reston the flat surface of the hub on the cam, D. On the disk G are threeelevations, g, Ag', g2, in position intermediate to the notches, f, f',f2, when the switch C is central. When the motor is at rest, the finger,F', rests the'notch,f, so that when the operator moves the cylinder, c,(which may be done by any well known means) the disk, F, moves withoutmoving the disk, G, the finger, F', preventing it moving, but causes theclutch plates to open and release the cam, D, until one of theelevations upon disk G comes in contact with the finger F', forcing thefinger out of the notch in disk, F, and, the disk, F, Ythen moves withdisk G, and the cam D is given a sudden movement, forcing the arm Eagainst pin l), moving arm B to the resistance and closing the circuitto the armature. This lifting the finger, F', from the notch, f,allows-.the clutch G' to go into action, and the plates close on theflat surface ofthe hub of cam D, stopping its movement. The movement ofdisk, F, before the clutch closes on the hub of cam D, is sufficient toallow the finger F2` on opposite side, to enter the notch f' orfz. Whenthe switch is operated to bring it toa central position, the disk F andcam D are held in the last mentioned position, the projection on disk Glifts the finger F2 from notch f' orf2, and the weight B', returns thearm quick-1y from the last resistance to the insulation. The movement ofthe arm E does not occur in the movement of the switch in eitherdirection until it has been sufficient to give a full and sudden throwto the cam, and thus insures a quick movementvof the arm B, to close thecircuit, causing no spark, and in breaking,r the circuit it causes thecurrent to be cut ofi:` quickly.

Having now fully described my invention, what I claim, and desire toprotect by Letters Patent, isl 1. In combination with atranslatingdevice, a reversing switch, a source of current supply, electricalconnection between the source of current supply and electric switch andbetween the switch and translating device, resistances in said lastmentioned circuit, au arm for controlling the amount of resistance insaid circuit, an insulation upony which said arm is adapted to rest atone end of its travel, mechanism to operate said switch and connectionbetween said mechanism and the resistance arm, the connection beingsuch, as, in the movement of the switch in either direction from thecenter, will move said arm from the insulation to the resistancecontacts and no farther. 2. In combination with a translating device, areversing switch, a source of current supply, electrical connectionbetween the source of current supply and electric switch and between theswitch and translating device, resistances in said last mentionedcircuit, an arm for controlling the amount of resistance in saidcircuit, an insulation upon which said arm is adapted `to rest at oneend of its travel,

mechanism to operate said switch Aand ,connection between said mechanismand the resistance arm, the connection being such, as, in the movementof the switch in either direction from the center will, move said -armfrom the insulation to the resistance contacts and no farther, and inthe movement of the switch to the center to allow said arm to return tothe insulation.

3. In combination with a resistance arm adapted to pass over resistancesand vary the resistance in the circuit of a translating device, aninsulation upon which said arm is adapted to rest at vthe end of itsmovement in one direction, a reversing switch interposed between saidtranslating device and thesourcev of current supply, and switchope-rating mechanism supported and adapted toslide, an arm one endresting against but not connected to said resistance arm, when said armis in insulation, and connection between said arm and the switchoperating mechanism, the connection being such that in the movement ofthe switch in either direction from central, the arm resting against theresistance arm is moved in one ldirection and said resistance arm isforced off of said resistance.

4. In combination with a resistance arm adapted to pass over resistancesand vary the resistance in the circuit of a translating device, aninsulation upon which said arm is adapted to rest at the end of itsmovement in one direction, a reversing switch. interposed between saidtranslating device and the source of current supply, and switchoperating mechanism supported and adapted to slide, an arm one endresting against but not connected to said resistance arm,lwhen said armis in insulation, and connection between said arm andthe switchoperating mechanism, the connection being such that in the movement ofthe switch vin either direction from central the arm resting against theresistance arm is moved in one direction, and said resistance arm isforced off of said resistance, and in the movement of the switch to thecenter said arm is moved in the other direction so that said resistancearm can return to insulation.

5. In combination with a resistance arm adapted to pass over resistancesand vary the resistance in the circuit of a translating de- ICC) IIO

vice, an insulation upon which said arm is adapted to rest at the end ofits movement in one direction, a reversing switch interposed betweensaid translating device and the source of current supply, and switchoperating mechanism, of an arm supported and adapted to slide, one endof said arm resting against but not secured to said resistance arm whensaid resistance arm is upon the insulation, a cam having two cam faces,the other end of the arm resting against resistance arm resting againstsaid cam, said cam being loose upon the shaft or extension of the shaftof the switch, a disk having notches secured to said cam, spring fingersadapted to rest in said notches, a disk fixed upon said shaft, andelevations 0n sin disk intermediate to the notches in notched disk, andadapted in the movement of said disk to strike the fingers ofthe notcheddisk, said last mentioned disks being in frictional contact, and aspring clutch connected to the disk fixed to shaft and adapted to restupon and hold the cam.

6. In combination with a translating device, a reversing switch, asource of current supply, electrical connection between the source ofcurrent supply and electric switch and between the switch andtranslating device, resistances in said last mentioned circuit, an armfor controlling the amount of resistance in said circuit, an insulationupon which said arm is adapted to restat one end of its travel,mechanism to operate said switch, a device connected with saidmechanism, but disconnected with said resistance arm, the arrangementbeing such that in the movement of the switch in either direction fromthe centerthe device will move the resistance arm.

7. In combination with a translating device,

a reversing switch, a source of current supply, electrical connectionbetween the source of current supply and electric switch and be tweenthe switch and translating device, resistances in said last mentionedcircuit, an arm for controlling the amount of resistance in saidcircuit, an insulation upon which said arm is adapted to rest at one endof its travel, mechanism to operate said switch, a device connected withsaid mechanism, but disconnected with said resistance arm, thearrangement being such that in the movement of the switch in eitherdirection from the center the device will move the resistance arm and inthe movement of the switch to the center al low said arm to return tothe insulation.

In testimony of which invention I have hereunto set my hand.

FRANK E. IIERDMAN. Witnesses:

" C. D. vI-Iov'r,

JOB FISH, Jr.

